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New hope for melanoma patients

ELEANOR HALL: Melanoma is the deadliest form of skin cancer and claims more than 1200 lives in Australia every year.

Many melanomas can be removed with surgery. But if the cancer spreads beyond the skin, chemotherapy and radiotherapy treatments are largely ineffective.

Now though a new class of drugs is offering hope to people suffering from advanced melanoma.

As Timothy McDonald reports results from the clinical trials will be presented in Sydney over the next few days.

TIMOTHY MCDONALD: More than 10,000 Australians are diagnosed with melanoma each year.

For some simply removing the cancer from the skin is enough but in other cases it spreads into the brain or liver.

Professor Richard Kefford from the Melanoma Institute of Australia says once it does it becomes very difficult to treat.

RICHARD KEFFORD: Melanoma cells are very resistant to traditional forms of anti-cancer treatment with radiation therapy and chemotherapy drugs.

They've got a remarkable series of defence mechanisms against being killed by those drugs. And that's why we haven't been able to make any progress up until now.

TIMOTHY MCDONALD: Several companies are trialling drugs that target a gene mutation in melanomas after they metastasise and generate secondary tumours in other parts of the body.

The companies will present their findings at the International Melanoma Congress in Sydney over the next few days.

Richard Kefford says the results so far have been very promising.

RICHARD KEFFORD: Well they're exploiting a specific abnormality in the tumour which was discovered about 10 years ago.

So a large number of these tumours have a particular mutation in a growth regulatory pathway that if you like leaves them with the accelerator permanently down.

And these drugs exploit the specific abnormality that's present. And they target it. And they turn off this feature and take the foot of the accelerator. And when that happens the cells die.

TIMOTHY MCDONALD: The new drugs target what are known as BRAF mutations which occur in half of all melanoma cases.

In preliminary tests for one of the drugs 70 per cent of patients with the mutation responded to the treatment.

Richard Kefford says it's potentially life-saving.

RICHARD KEFFORD: In a significant number of patients the cells travel to distant parts of the body and lodge in the liver and brain.

And every day in Australia 10 Australians develop that form of distant or what we call metastatic melanoma. And most of those patients will die within 12 months.

And the reason they die is that we haven't had any drug treatments that really effectively kill melanoma cells. What we are now seeing is a whole family of drugs that attack vulnerable aspects of the biochemistry of melanoma cells and kill them and do it very specifically without causing damage to other normal cells.

Professor Ian Olver is the CEO of the Cancer Council. He says it's possible that the treatment could be applied to other cancers as well.

IAN OLVER: There's the possibility that we've now looked more closely at that mutation in other cancers and apply the drug to this. But there's about 50 per cent of melanomas that would be expected to have this BRAF mutation in the gene. And so it's a good one to start with.

TIMOTHY MCDONALD: Ian Olver says the drugs are part of a new approach to treating cancer which targets specific genetic weaknesses to target the illness.

IAN OLVER: We already have marketed drugs in breast cancer where this has been very effective.

And it does two things. It's a better approach because it targets something that's specific to the tumour; and it's also usually a far less toxic approach.

And so it looks good for the future and it's quite a shift in the way we think about cancers based on our better knowledge of the mechanisms of the cause of cancer which go right back to changes in genes.

TIMOTHY MCDONALD: Melanoma is the third most common cancer in Australia and the most common for younger adults.

The most recent figures show that the disease is becoming more common for both men and women.